no, I didn’t delete anything from the db bevor. I have a known thread of emails from 54 people right know. they all swore they sent only to one recipient. but all the other 53 can read this message. we have this problem with and without caching.

Henry asked: “Can you try deactivating all plugins aside from BP to see if the problem persists?”

If you are unable or don’t want to turn of all other plugins, you could look into setting up a clone of the site or a local development environment to make it easier to debug in the future.

We need a list of your theme and all your plugins — while I hope this isn’t a core bug, a common cause of weird behaviour is a badly-written plugin or theme code interfering with the correct behaviour, which is why we need to know more about what you’ve got on your site.

I already have a clone of my site, but without members producing content and writing (lots of) private messages I cannot reproduce the error. @djpaul if you are interestet to have a deeper look under the hood, I would be happy to send you login data for community & db.

Caching BuddyPress often leads to problems in my experience. There are other methods to speed it up. Do you need all of those plugins. They’re all doing things (writing to the DB possibly) and many probably load their own JS and CSS files. That is part of what bogs down site speed.

For the email issue, did you happen to migrate your database at any point in time? In the DB users and messages are all tied to each other and it’s possible that the IDs got messed up in your DB somehow, so messages are going to the wrong recipients.